严重事故下水蒸气凝结对气溶胶扩散泳影响研究

Study on Effect of Steam Condensation on Aerosol Diffusiophoresis in Severe Accident Condition

基于模拟AP系列非能动安全壳冷却的气溶胶迁移机理试验平台,开展了在干燥及潮湿气氛下的气溶胶沉积试验。结果表明:在潮湿气氛下,气空间内气溶胶浓度会由于扩散泳沉积作用而衰减得更快,且水蒸气的凝结质量流量越大,气溶胶浓度衰减越快。证实了非能动安全壳冷却设计能够通过提高扩散泳沉积作用而强化气空间的气溶胶衰减。利用该特点,可针对性地采取措施增强水蒸气凝结,强化气溶胶扩散泳作用,提高安全壳内的放射性去除效果。

The experiments about aerosol deposition under dry and wet conditions were carried out on aerosol transport test facility which simulates AP series passive containment cooling.The results show that aerosol in atmosphere attenuates rapidly under wet condition due to diffusiophoresis deposition,in addition,the bigger the mass flux of steam condensation is,the rapider the aerosol attenuation speed is.It is confirmed that the design of passive containment cooling can enhance aerosol decay in bulk atmosphere by improving diffusiophoresis deposition.By taking the advantage of this feature,the reduction of radioactivity in containment can be enhanced through improving diffusiophoresis deposition of aerosol by increasing steam condensation.